Close a mountain pass for winter, even when winter wraps around the year end

The pass is shut from late autumn until early spring, which means from day 300 to day 60 of the next year, and a simple range check says it is never closed. Here is the right test, how long to wait, and when a trip should set out to arrive in time.

Why this works

A year is a circle, and a winter that starts in one year ends in the next. Asking whether a day lies in the window must therefore allow for the wrap, and a trip must be judged on the day it arrives at the pass, not on the day it sets out.

When not to use it

Skip it when closures depend on the weather and change from year to year; a fixed window will be wrong. Then roll the weather for each day, or let a story event decide, and use this only for fixed seasons.

In the full entry

• What to build, step by step
• Starting values and the reason for each
• 4 common mistakes and the fix
• A diagram of every state
• 19 lines of example code with 3 checks that pass
• How your AI shows you that it works

Say this to your AI

Use the Spielerando entry "Close a mountain pass for winter, even when winter wraps around the year end" (read_entry mountain-pass-closed-over-the-new-year) in my game. Build it step by step, and show me how you checked that it works.

Or skip this and connect the MCP: your AI then finds all of this by itself.Connect the MCP